The present invention relates generally to plastic containers, and in particular a plastic fuel tank for a motor vehicle, having components arranged on the walls of the plastic container.
Plastic containers designed as fuel tanks are used in modern motor vehicles. In order to enable the internal combustion engine to be supplied with fuel from the fuel tank in every situation, and on account of the complicated shapes which such a plastic container may have, a multiplicity of subassemblies, e.g., a delivery unit, suction jet pumps, valves and pressure regulators, are necessary in the interior of the plastic container.
In relation to the production process, it is possible to distinguish between two types of plastic containers. So-called blow-molded plastic containers are forced, as a freshly extruded tube, into a mold with an internal pressure, with the result that the tube positions itself against the wall of the mold. Thereafter, the components are introduced into the blow-molded plastic container, and installed therein, via the introduction opening and additional installation openings. On account of the configurations of the plastic container, the installation is often very difficult and is only possible with high outlay.
Improved installation is possible in plastic containers which are produced by means of injection molding. The plastic container is produced from two injection-molded half-shells which are welded to one another. The installation of all the components takes place in the half-shells before the welding operation. The disadvantage with this is that the components have to be fixed in their position in order to remain in said position at all times. Thus, the suction jet pumps and the delivery unit have to be fastened at the lowermost point in the plastic container, in order to allow complete emptying as far as possible and also, in the case of a minimal filling level, to ensure that the internal combustion engine is supplied reliably with fuel. The fastening often takes place by means of clamps or welding. The installation outlay and the costs for such plastic containers are thus still very high.
Thus, there is a need for a plastic container with the installation outlay required for components which are to be arranged in its interior being considerably reduced in relation to conventional containers.
Other needs will become apparent upon a further reading of the following detailed description taken in conjunction with the drawings.
In one form of the invention, the aforementioned needs are fulfilled by a plastic container comprising two injection-molded half-shells in which, during the production process, parts of components which are to be arranged in the plastic container are integrally formed on the wall of the half-shells by means of injection molding.
The advantage of these plastic containers is that, by virtue of parts of the components being attached by injection molding, they are already fastened on the plastic container, thus doing away with subsequent fastening of the components during installation. In addition to cutting back on fastening means, the installation process is thus simplified to a considerable extent and is consequently considerably more cost-effective than the installation of components in prior-art plastic containers.
A further advantage is that, as a result of the now predetermined position of the constituent parts attached by injection molding, installation errors are largely ruled out. It is also the case that the production of the plastic containers according to the invention involves less outlay than the prior-art production since a multiplicity of the parts may be produced in conjunction with cores by corresponding configuration of the injection molds.
In an advantageous configuration of the invention, the parts are designed as housings. These housings may be constituent parts of a wide range of different components, such as valves, pressure regulators, filters, level sensors or pumps. In particular when the plastic container is used as a fuel tank, it is advantageous if a splash pot or baffle plates are attached by injection molding to the container inner wall of the half-shell which forms the bottom region.
A particularly advantageous configuration is achieved when, in addition to a housing, further functional parts, e.g., valve housings with a valve seat, are attached by injection molding. In the subsequent installation, all that is then required is for the closing and actuating element to be placed in position and fixed correspondingly.
Furthermore, it is advantageous for parts to have bores for the connection of connecting lines. It is likewise possible for the parts to have connection stubs.
In a particularly advantageous manner, the parts of the components are arranged on lines which are produced by the internal gas pressure method and are integrated in the plastic container. Such parts may be valve housings or suction jet pumps. In particular, the arrangement of crash valves, which in the event of disruption avoid fluids running out of the lines, is very advantageous. This configuration makes it possible to cut back on connecting locations between individual components, which results in not inconsiderable savings in cost terms.
The configurations of the plastic container according to the invention, however, are not restricted just to parts of components which are arranged in its interior. It is likewise possible, in the case of corresponding requirements, for the parts to be arranged on the outsides of the plastic container.
The plastic container is thus particularly suitable as a fuel tank for a motor vehicle. It is also suitable, however, for all other application areas in which components are connected, as inserts or add-on elements, to the plastic container, thus, for example, as containers of a window-cleaning installation or as cooling-water tanks.